B&B Electronics RS-232 Digital I/O Module 232SDD16 - Manual (Page 15)

232SDD16-1005 Manual 25
B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350
PH (815) 433-5100 -- FAX (815) 433-5104
Define I/O Lines Command
Step 1a - Construct the command string:
Define an I/O line as Output
MSdefs = MSdefs OR mask
LSdefs = LSdefs OR mask
By "ORing" the current definitions with the appropriate I/O line
mask, the I/O line's data bit will be set to a "1" (HIGH) and the I/O
line will be defined as an Output.
Step 1b - Define an I/O line as an Input
MSdefs = MSdefs AND (NOT(mask))
LSdefs = LSdefs AND (NOT(mask))
By "ANDing" the current definitions with the complement of the
appropriate I/O line mask the I/O line's data bit will be set to a "0"
(LOW) and the I/O line will be defined as an Input.
Step 1c - Completing the command string:
Cmnd$ = "!0SD" + CHR$(MSdefs) + CHR$(LSdefs)
Step 2 - Transmitting the command string:
Print #1, Cmnd$;
Example 5.4 - Define I/O line #7 as an Output (HIGH) and I/O line #8
as an input (LOW).
'Set bit 7 of LSdefs to make I/O line #7 an Output (HIGH).
LSdefs = LSdefs OR &H80
'Clear bit 0 of MSdefs to make I/O line #8 an Input (LOW).
MSdefs = MSdefs AND (NOT(&H1))
Cmnd$ = "!0SD" + CHR$(MSdefs) + CHR$(LSdefs)
Print #1, Cmnd$;
MSIO$ = INPUT$(1,#1)
I/O #7 will be defined as an Output (HIGH) and I/O line #8 will be
defined as an Input (LOW). All other I/O definitions will not be
changed.
Set Power-up States Command
Step 1a - Construct the command string:
Set appropriate outputs power-up states HIGH
MSpups = MSpups OR mask
LSpups = LSpups OR mask
By "ORing" the current power-up states with the appropriate
mask of a digital output line, the power-up state's data bit will be
set to a "1" (HIGH).
26 232SDD16-1005 Manual
B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350
PH (815) 433-5100 -- FAX (815) 433-5104
Step 1b - Set appropriate outputs power-up states LOW
MSpups = MSpups AND (NOT(mask))
LSpups = LSpups AND (NOT(mask))
By "ANDing" the current power-up states with the complement of
the appropriate mask of a digital output line, the power-up state's
data bit will be set to a "0" (LOW).
Step 1c - Completing the command string:
Cmnd$ = "!0SS" + CHR$(MSpups) + CHR$(LSpups)
Step 2 - Transmitting the command string:
Print #1, Cmnd$;
Example 5.5 - Set Output line #5's power-up state HIGH and Output
line #13's power-up state LOW.
'Set bit 0 of LSpups to make Output #5's power-up state HIGH.
LSpups = LSpups OR &H20
'Clear bit 4 of MSpups to make Output #13's power-up state LOW.
MSpups = MSpups AND (NOT(&H20))
Cmnd$ = "!0SS" + CHR$(MSpups) + CHR$(LSpups)
Print #1, Cmnd$;
MSIO$ = INPUT$(1,#1)
Output #5's power-up state will be set HIGH and output #13's
power-up state will be set LOW. All other output power-up states
will not be changed.